The invention relates to a medical instrument for manipulation of an uterus, with a rod-shaped body whose distal end section can be inserted through the vagina into the uterus, said rod-shaped body carrying a bell-shaped element that can be moved to and fro along the rod-shaped body.
A medical instrument that is used for manipulation of an uterus and that has these design features is known from US 2003/0187334 A1.
Medical instruments of this kind, also called uterus manipulators, are used, among other reasons, to bring the uterus to a desired position for laparoscopic examinations of the lower abdominal region of female patients or in preparation for a surgical intervention. This is done, for example, in order to be able to examine a concealed surface of the uterus or to perform a surgical intervention, for example a hysterectomy (removal of the uterus).
The medical instrument mentioned at the outset has a rectilinear rod, which is provided with a coarse external thread along almost the whole of its length. A bell-shaped element sits on the external thread and can be moved to and fro along the rod by rotation. By means of a relative rotational movement between the bell-shaped element and the rod, the axial position of the bell-shaped element on the rod can be changed. In this relative rotational movement, the bell-shaped element can be held securely by the operator, and the rod is rotated, or the rod is held securely by the operator, and the bell-shaped element is rotated.
To manipulate the uterus, the bell-shaped element is first fitted on the distal end section of the rod. The rod, with the bell-shaped element arranged on its distal end section, is then inserted into the vagina until the bell-shaped element encloses the mouth of the uterus. The bell-shaped element is held securely in this position by the wall of the vagina. The rod provided with the coarse thread is then rotated by the operator such that it is driven into the uterus. With the instrument positioned in this way, the operator is able to manipulate the uterus by moving the rod, in order to perform an examination or a surgical intervention.
A disadvantage of this medical instrument is that the axial position of the bell-shaped element on the rod is changed by a rotational movement between the bell-shaped element and the rod. In order to move the bell-shaped element from a proximal end to a distal end, the operator has to turn either the rod of the bell-shaped element approximately 20 to 25 times. This is awkward, and quite a long time is taken to insert and position the medical instrument in the body of the patient.
A further disadvantage of said instrument is that the bell-shaped element is arranged on the distal end section of the rod when the latter is inserted into the uterus. As a result, the distal end section of the rod is not visible to the operator. He is therefore unable to check the position of the distal end section of the rod that is rotated into the uterus and is therefore also unable to correct it. This can have the effect that a wrongly positioned distal end section of the rod does not move into the cavity of the uterus and is instead driven into the tissue of the uterus, as a result of which the sensitive tissue may be damaged by the coarse thread. The coarse thread poses a danger of tissue areas attaching to it and being rotated with it, with the result that the cervix becomes twisted.
The object of the invention is therefore to further develop a medical instrument of the type mentioned at the outset, in such a way that the insertion and positioning of the instrument in the body of the patient can be performed easily and quickly by the operator and in a manner that causes minimal trauma to the patient.